In the past, the matter of moving a mechanical element from one position to another where the two positions are defined by, say, a set of orthogonal units (x, y, z) has been accomplished serially by first moving to the new x location, then to the new y and finally to the new z. This kind of motion control was practically achieved through the use of servomotors and generators which were accompanied by well-known deficiencies and inaccuracies. Later, more acccuracy was obtained by using so-called step motors which provide a highly precise angular shaft output on being electrically pulsed.
In all known prior motion control apparatus, change in position was not accomplished vectorially, but rather along one axis at a time, namely x1-x2, y1-y2 and z1-z2. This meant that the time allotted for any change in position of a mechanical element was of necessity the summation of the individual times required for moving required amounts on each of the control axes which could be prohibitive.